// CodeMirror, copyright (c) by Marijn Haverbeke and others
// Distributed under an MIT license: http://codemirror.net/LICENSE

(function(mod) {
  if (typeof exports == 'object' && typeof module == 'object')
    // CommonJS
    mod(require('../../lib/codemirror'));
  else if (typeof define == 'function' && define.amd)
    // AMD
    define(['../../lib/codemirror'], mod);
  // Plain browser env
  else mod(CodeMirror);
})(function(CodeMirror) {
  'use strict';

  CodeMirror.defineMode('turtle', function(config) {
    var indentUnit = config.indentUnit;
    var curPunc;

    function wordRegexp(words) {
      return new RegExp('^(?:' + words.join('|') + ')$', 'i');
    }
    var ops = wordRegexp([]);
    var keywords = wordRegexp(['@prefix', '@base', 'a']);
    var operatorChars = /[*+\-<>=&|]/;

    function tokenBase(stream, state) {
      var ch = stream.next();
      curPunc = null;
      if (ch == '<' && !stream.match(/^[\s\u00a0=]/, false)) {
        stream.match(/^[^\s\u00a0>]*>?/);
        return 'atom';
      } else if (ch == '"' || ch == "'") {
        state.tokenize = tokenLiteral(ch);
        return state.tokenize(stream, state);
      } else if (/[{}\(\),\.;\[\]]/.test(ch)) {
        curPunc = ch;
        return null;
      } else if (ch == '#') {
        stream.skipToEnd();
        return 'comment';
      } else if (operatorChars.test(ch)) {
        stream.eatWhile(operatorChars);
        return null;
      } else if (ch == ':') {
        return 'operator';
      } else {
        stream.eatWhile(/[_\w\d]/);
        if (stream.peek() == ':') {
          return 'variable-3';
        } else {
          var word = stream.current();

          if (keywords.test(word)) {
            return 'meta';
          }

          if (ch >= 'A' && ch <= 'Z') {
            return 'comment';
          } else {
            return 'keyword';
          }
        }
        var word = stream.current();
        if (ops.test(word)) return null;
        else if (keywords.test(word)) return 'meta';
        else return 'variable';
      }
    }

    function tokenLiteral(quote) {
      return function(stream, state) {
        var escaped = false,
          ch;
        while ((ch = stream.next()) != null) {
          if (ch == quote && !escaped) {
            state.tokenize = tokenBase;
            break;
          }
          escaped = !escaped && ch == '\\';
        }
        return 'string';
      };
    }

    function pushContext(state, type, col) {
      state.context = {
        prev: state.context,
        indent: state.indent,
        col: col,
        type: type,
      };
    }
    function popContext(state) {
      state.indent = state.context.indent;
      state.context = state.context.prev;
    }

    return {
      startState: function() {
        return { tokenize: tokenBase, context: null, indent: 0, col: 0 };
      },

      token: function(stream, state) {
        if (stream.sol()) {
          if (state.context && state.context.align == null)
            state.context.align = false;
          state.indent = stream.indentation();
        }
        if (stream.eatSpace()) return null;
        var style = state.tokenize(stream, state);

        if (
          style != 'comment' &&
          state.context &&
          state.context.align == null &&
          state.context.type != 'pattern'
        ) {
          state.context.align = true;
        }

        if (curPunc == '(') pushContext(state, ')', stream.column());
        else if (curPunc == '[') pushContext(state, ']', stream.column());
        else if (curPunc == '{') pushContext(state, '}', stream.column());
        else if (/[\]\}\)]/.test(curPunc)) {
          while (state.context && state.context.type == 'pattern')
            popContext(state);
          if (state.context && curPunc == state.context.type) popContext(state);
        } else if (
          curPunc == '.' &&
          state.context &&
          state.context.type == 'pattern'
        )
          popContext(state);
        else if (/atom|string|variable/.test(style) && state.context) {
          if (/[\}\]]/.test(state.context.type))
            pushContext(state, 'pattern', stream.column());
          else if (state.context.type == 'pattern' && !state.context.align) {
            state.context.align = true;
            state.context.col = stream.column();
          }
        }

        return style;
      },

      indent: function(state, textAfter) {
        var firstChar = textAfter && textAfter.charAt(0);
        var context = state.context;
        if (/[\]\}]/.test(firstChar))
          while (context && context.type == 'pattern') context = context.prev;

        var closing = context && firstChar == context.type;
        if (!context) return 0;
        else if (context.type == 'pattern') return context.col;
        else if (context.align) return context.col + (closing ? 0 : 1);
        else return context.indent + (closing ? 0 : indentUnit);
      },

      lineComment: '#',
    };
  });

  CodeMirror.defineMIME('text/turtle', 'turtle');
});
